I’ve tried lots of different options for music management: iTunes, Google Music, Spotify, Subsonic, and others. All of them have different problems. For iTunes, you’re tied to Apple devices. For Google Music, you have to start over organizing and rating your music, as it has no public API and doesn’t really attempt to sync metadata besides your playlists in a limited fashion. Spotify, similar story. Subsonic doesn’t reflect your changes in iTunes and maintains its own database separate from your iTunes library. Organizing via a flat file system is cumbersome, doesn’t sync to devices easily, and doesn’t have a lot of niceties such as ratings and playlists.